The hosts were roared on by a noisy Geneva crowd and took the lead in the 10th minute when Udinese midfielder Gokhan Inler fired the ball in at the near post from 20 metres with goalkeeper Federico Marchetti exposed.
Italy hit back five minutes later as striker Fabio Quagliarella, who surprised pundits by being named in the World Cup squad, looped in a header off the far post.
Swiss midfielder Valon Behrami, substituted with a suspected groin problem, had arguably the best chance to win the game when his shot was deflected over while Giampaolo Pazzini almost scrambled Italy ahead in the second period.
"Behrami was playing very direct and looked threatening. I hope it's not serious. We go to South Africa well-prepared," Switzerland coach Ottmar Hitzfeld told a news conference.
Italy's Marcello Lippi, whose strongest side lost 2-1 to Mexico on Thursday, played mostly a second string team and included Cossu for the first half given Andrea Pirlo and Mauro Camoranesi could be forced to miss the tournament through injury.
SHAKY DEFENCE
Cossu is set to fly with the squad to South Africa as a 24th man and can be drafted into the squad before June 13 if either of the World Cup-winning pair withdraw.
Pirlo will definitely miss Italy's Group F opener against Paraguay in Cape Town on June 14 and and could struggle to make any group games but Camoranesi's knee injury is improving.
Hitzfeld, whose team open their Group H campaign against Spain on June 16, started a strong side and they were a threat down the flanks with Italy's shaky defence forced into some last-gasp tackles.
Cossu played wide right in a 4-2-3-1 formation but was overshadowed by midfielder Riccardo Montolivo, who showed some neat touches as he pushes to be Pirlo's replacement.
"It was an encouraging performance, we are getting better," Lippi said.
"In South Africa we will continue our programme to try to recapture our shine and speed. You will see, on the 14th we will be ready."
The Azzurri still looked nothing like world champions in their final warm-up but their customary slow starter tag will console them somewhat, even if injuries are threatening to ruin their preparations.
Angelo Palombo went off clutching his knee and will undergo checks while fellow midfielder Claudio Marchisio also has a minor calf problem. However, first choice centre-back Giorgio Chiellini played the full game after recovering from a niggle.
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